export default {
  namespaced:true,
  state: () => ({
    cart:JSON.parse(uni.getStorageSync('cart') || '[]')
  }),
    
  mutations:{
    // 加入到购物车的方法
    addToCart(state,goods){
      const findResult = state.cart.find((x) => x.goods_id === goods.goods_id)
      if(!findResult){
        state.cart.push(goods)
      }else{
        findResult.goods_count += 1
      }
      // 通过commit方法,调用m_cart命名空间下的saveToSorage方法
      this.commit('m_cart/saveToStorage')
    },
    
    // 将购物车中的数据持久化存储到本地
    saveToStorage(state){
      uni.setStorageSync('cart',JSON.stringify(state.cart))
    },
    
    // 更新购物车中勾选商品的状态
    updateGoodsState(state,goods){
      const findResult = state.cart.find(x => x.goods_id === goods.goods_id)
      if(findResult)
      findResult.goods_state = !findResult.goods_state
      this.commit('m_cart/saveToStorage')
    },
    
    // 更新购物车中商品的数量
    updateGoodsCount(state,goods){
      const findResult = state.cart.find(x => x.goods_id === goods.goods_id)
      if(findResult){
        findResult.goods_count = goods.goods_count
        this.commit('m_cart/saveToStorage')
      }
    },
    
    // 删除购物车内的物品
    delGoodsById(state,goods){
      state.cart = state.cart.filter(x => x.goods_id !== goods.goods_id)
      this.commit('m_cart/saveToStorage')
    },
    
    // 更新所有商品的勾选状态
    updateAllState(state,newState){
      state.cart.forEach(x => x.goods_state = newState)
      this.commit('m_cart/saveToStorage')
    }
  },
  getters:{
    // 统计购物车中商品的数量
    total(state){
      let c = 0
      state.cart.forEach(x => c += x.goods_count)
      return c
    },
    // 勾选商品的总数量
    checkedCount(state){
      // return state.cart.filter(x => x.goods_state).reduce((total, item) => total += item>goods_count, 0)
      return state.cart.filter(x => x.goods_state).reduce((total, item) => total += item.goods_count, 0)
    },
    
    // 计算商品的总价
    amount(state){
      let a = 0
      state.cart.filter(x => x.goods_state).forEach(item => a += item.goods_count * item.goods_price)
      return a
    }
  }
  

}